Electrical apparatus for producing sound-signals



No. 752,408. VPATENTED FEB. 16, 1904.

G. H. OBRIEN.

ELECTRICAL APPARATUS FOR PRODUCING SOUND SIGNALS.

APPLICATION FILED NOV.1'1902. I

KO MODEL.

Pi G- 1.

E d 3 a a v (j l 17 J3 E Y 6km UNITED: S AT Patented February 16, 1904.

PATENT OFFICE.

CHARLES H. OBRIEN,- or AUGUSTA, MAINE.

ELECTRICAL APPARATUS FOR PRODUCING SOUND-SIGNALS.

SPECIFICATION formingpart of Letters Patent N0. 752,408, dated February 16, 1904.

Application filed November 1,1902. $eria1No. 129,667. (Nomodel) To al /Z whom it may concern:

Be it known that I, CHARLES H. OBRIEN, a citizen of the United States of America, and a resident of Augusta, county of Kennebec, State of Maine, have invented certain new and use-r ful Improvements in Electrical Apparatus for Producing Sound-Signals, of which thefollowing is a specification.

My invention relates to an electrical device for producing sound-signals through the rapid vibrations of a diaphragm; and'the object of the invention is to produce a signaling device of great power for use on electric street cars, locomotives, and the like and also for all of the various uses to which bells, whistles, and other signaling means may be put.

The invention consists, essentially, of an induction-coil having the primary coil wound on an iron tube, with a permanent magnet inside of said tube, and having a winding connecting with the secondary coil and a diaphragm adjacent to and subject to the action of both the permanent magnet and the iron tube, which becomes a magnet when the current is on. vibrator is provided for rapidly making and breaking the primary circuit and a resonatingchamber and mouthpiece connecting with the resonating-chamber for increasing the sound. The diaphragm being acted upon at the same time by both the permanent magnet and the magnetized iron core produces an intense sound suitable for a signal.

By constructing a coil having both the primary and secondary windings the current causes the vibrator to be rapidly vibrated, thus producing a double action on the diaphragm, and the result is that a much more intense sound than could be produced by a single induction-coil is produced by this construction, and thus it will be seen that by the use of this construction of induction-coil, in combination with the arrangement of the diaphragm and megaphone attachment the volume of sound created by the rapid vibrating of the diaphragm is multiplied and that a louder signal is caused to be made.

I illustrate my invention by means of the accompanying drawings, in which Figure l is a vertical longitudinal section through the apparatus, showing the connections diagrammatically; and Fig. 2 is a section on the line 00 so of Fig. 1.

A represents the permanent magnet, which is placed within the hollow iron core B, on which is the primary winding C. Over the primary winding is the secondary winding D, connecting, by means of the wires a, with the winding of the permanent magnet. The primary winding is in circuit, as shown, with the battery it and with a vibrator i by means of wires Z and y, or it may be connected with any suitable supply of current under rapid vibration, as an alternating-current generator, the essential thing being thatthe primary circuit be in a state of rapid vibration. End pieces E are supplied to hold the parts in place, and adjacent to the ends of the permanent magnet and the hollow core there is a metal diaphragm f, inclosed in a resonating-chamber g, formed by the casing g, with a megaphone or horn it for throwing out the sound.

When the primary circuit is rapidly vibrated, the secondary circuit is also vibrated, and both the permanent magnet and the hollow core act together on the diaphragm to produce a rapid vibration and the production of a loud sound.

The device may be used for a great number of purposes where signals, whistles for streetcars, and the like are used.

.I claim 1. In an electrically-operated device for producing sound-signals, the combination of a hollow iron core a rimar winding surrounding said core, a secondary winding surrounding the primary winding, a permanent magnet mounted within the iron core and having its ends terminating in line with one end of the core, wires wrapped around the ends of the primary magnet and connected to the secondary winding, a battery-circuit in connection with the primary winding, disks mounted upon each end of the iron core for holding the parts together, a metal diaphragm placed over one end of the metal core, and the ends of the permanent magnet, a removable cap secured to the metal core for holding said diaphragm in its proper relation hollowed out upon the inner side to provide a resonating-chamber, and a megaphone mounted in-said cap and in communication with the resonating-chamber.-

2. In an electrical device for producing sound-signals, the combination of a hollow iron core, a primary winding surrounding said ing, means to holdthe parts together, a metal diaphragm placed over the ends of the metal 15 core and permanent magnet, a cap holding said diaphragm in its proper relation and providinga resonating-chamber, and a megaphone mounted in said cap for the purpose set forth.

, Signed atAugusta, Maine, this 24th day of 20 October, 1902.

' CHARLES H. OBRIEN.

Witnesses:

A. G. VosE, D. M. LIPPINCOTT. 

